3) Use MATLAB's fminbnd() function to find the maxima and minima of the following functions and graph the curves accordingly: a. f(x)=x+10x3 - 20x - 15 b. f(x) e(-0.5x) sin 2x c) Use the method of steepest descent MATLAB code to obtain the approximate position that makes fa relative minimum where f(x,x)=8x-20xx +17x-32x+40x2 = 0.03, and 230 steps. Use (x1, x2)=(6, 4) as the starting point, As